1. Field of the Invention
The present invention relates to harvesting apparatus and methods, and in particular relates to apparatus designed to harvest aquatic weeds.
2. Description of the Prior Art
There are two types of fresh water aquatic weeds which presently cause considerable ecological and economic harm in certain areas of the United States, particularly in the warmer regions, such as Florida and other southeastern states.
One of these aquatic weeds is Eichhornia Crassipes Mart. Solmes, commonly referred to as "water hyacinths". These plants grow on the surface of the water with root structures extending only a few inches, on the order of five to twenty inches, below the surface; and grow in densities ranging between forty to one hundred fifty tons per acre, in fresh water bodies ranging from small canals and lakes to very large lakes and rivers.
The second of these aquatic weeds is Hydrilla Verticillata Royale, commonly referred to as "hydrilla". Hydrilla is a submerged, rooted plant which grows to a height where sufficient sunlight permits blooming. The density of hydrilla growth typically ranges from eight to twenty tons per acre.
Numerous systems and methods have been developed in the prior art for harvesting aquatic weeds. Examples of such arrangements are disclosed in the following United States patents: U.S. Pat. No. 3,866,396 to Meyer; U.S. Pat. No. 3,884,018 to Chaplin; U.S. Pat. No. 2,648,940 to Merkley, et al.; U.S. Pat. No. 3,130,531 to Woleslagle; U.S. Pat. No. 2,677,926 to Washbourne, et al.; U.S. Pat. No. 3,599,354 to Larson; U.S. Pat. No. 644,885 to Allen; U.S. Pat. No. 3,601,956 to Akermanis; and U.S. Pat. No. 3,971,148 to Deal.
Some prior art aquatic weed harvesting systems have been unable to harvest aquatic weeds in sufficient quantities to economically justify their operation. Systems which have sufficient harvesting rates have been characterized by rotating cutting heads, or suction heads which are submerged in proximal relation to the hydrilla, when being harvested. See for example, U.S. Pat. No. 3,971,148 and U.S. Pat. No. 3,866,396, referred to above. However, these systems disturb the loose silt or sand bottom customarily found in fresh water lakes and rivers. This, in turn, can result in long term damage to the ecological balance of the body of water. Because of the severity of this problem, some states have passed regulations which restrict the amount of soil disturbance that can take place during aquatic weed harvesting operations.